Biology subjects

Chanda, A.

Publications and source records attributed to Chanda, A..

7 recordsLinked to original sources

bioRxiv2026

Mucosal ACP subunit vaccine formulated with a small molecule STING agonist drives protective TH1/TH17 responses and serum bactericidal antibodies against Neisseria gonorrhoeae

STING agonists are emerging vaccine adjuvants; however, only cyclic dinucleotides (low permeability and stability) have been tested against pathogenic bacteria. We examined diABZI, a non-nucleotide STING agonist active in human and murine orthologs, combined with the Neisseria gonorrhoeae (Ng) Adhesin Complex Protein, a conserved adhesin and human lysozyme C inhibitor, as a gonococcal vaccine. Intranasal administration of recombinant ACP (rACP)+diABZI accelerated gonococcal clearance, in contrast to rACP or rACP+CpG+MPLA, despite comparable antibody responses. While both diABZI and CpG+MPLA induced TH1, diABZI also induced TH17 polarization. Peptide mapping localized the immunodominant T cell epitopes to the ACP-lysozyme C interface. rACP+diABZI elicited higher human serum bactericidal activity (hSBA), that correlated with Ng clearance, and antibodies that reversed human lysozyme C inhibition and interfered with Ng adhesion and invasion in 3D human vaginal/urethral mucosal models. Passive serum transfer did not recapitulate protection, implicating mucosal antibodies and cellular immunity over circulating IgG.

microbiology↗

bioRxiv2026

PIAS1 loss and INHBA gain define a TGFβ-driven EMT state in OSCC progression

Oral squamous cell carcinoma (OSCC), a highly aggressive subtype of head and neck cancer, remains a major clinical challenge with limited therapeutic options and poor survival outcomes. The Protein Inhibitor of Activated STAT1 (PIAS1), a SUMO E3 ligase involved in transcriptional regulation, DNA repair, and epithelial-mesenchymal transition (EMT), exhibits cancer type-specific roles, but its function in OSCC has not been well characterized. Here, we investigated the molecular and functional role of PIAS1 in OSCC progression and prognosis. All patient cohorts analysed here comprise HPV-negative disease. Analysis across multiple cohorts revealed that PIAS1 mRNA expression is significantly lower in tumor tissues than in normal oral cavity squamous epithelium, including in a cohort of 60 patient-matched tumor and normal pairs. Within the tumor compartment, protein abundance of PIAS1 correlated positively with patient survival. Functional assays using OSCC cell lines demonstrated that PIAS1 acts in a SUMO E3-dependent manner to suppress TGF{beta}-induced migration and invasion. Transcriptomic profiling of PIAS1-depleted cells revealed alterations in expression of genes with relevance in TGF{beta} signaling and pro-invasive cellular responses. Further analyses showed that 46 of these differentially altered hits intersected with The Cancer Genome Atlas (TCGA)-OSCC datasets, where four of these genes, including INHBA, associated with cell stemness-pathway. Spatial analysis of the mRNA abundance of INHBA within OSCC-derived surgical specimens showed increased abundance at the invasive front, and positively associated with aggressive tumor phenotypes, poor patients' outcomes, and resistance to immunotherapy. Single-cell RNA-seq analyses of INHBA revealed increased levels within tumor cells and cancer-associated fibroblasts (CAFs), suggesting potential tumor-intrinsic and extrinsic (tumor microenvironment) sources and hence actions. Collectively, our findings establish PIAS1 as a tumor suppressor in OSCC that restrains TGF{beta}-driven aggressive behaviour. Furthermore, we identify INHBA as a potential therapeutic target, among other genes characterized by spatially restricted, invasive tumor phenotypes.

cancer biology↗

bioRxiv2026

An mRNA-Lipid Nanoparticle Platform Encoding the Conserved Outer Membrane Protein BamA Elicits Broadly Cross-Reactive Systemic and Mucosal Antibodies Against Antimicrobial-Resistant Neisseria gonorrhoeae

Neisseria gonorrhoeae (Ng) is the causative agent of gonorrhea, and the global spread of antimicrobial-resistant strains makes vaccine development a public health priority. Although messenger RNA (mRNA) vaccines have transformed protection against viral diseases, the platform remains in its infancy against pathogenic bacteria. Here, we evaluated the immunogenicity and protective efficacy of an mRNA-lipid nanoparticle (LNP) vaccine encoding the highly conserved outer membrane antigen BamA in the female mouse model of lower genital tract infection. We delivered BamA mRNA-LNPs via intramuscular (IM) or intranasal (IN) routes, with or without CpG ODN 2395, and measured antigen-specific antibody responses in serum and vaginal lavage samples. Both routes elicited robust BamA-specific antibodies that recognized diverse Ng isolates, including ceftriaxone-resistant strains. However, neither route accelerated bacterial clearance nor reduced bioburden, nor did either generate serum bactericidal activity. These findings show that BamA mRNA-LNPs are immunogenic but, as formulated, are not protective, and they pave the way for modifications to the construct, adjuvant, and route. To our knowledge, this is the first evaluation of an mRNA vaccine against Ng, establishing the platform as an amenable approach for gonococcal antigen testing. ImportanceNeisseria gonorrhoeae is a high-priority public health threat, and no licensed gonococcal vaccine exists. mRNA-lipid nanoparticle vaccines have transformed antiviral immunization but remain largely untested against bacterial pathogens. This study is the first to evaluate an mRNA vaccine against N. gonorrhoeae, using the conserved, essential outer membrane antigen BamA. We show that BamA mRNA-LNPs delivered by intramuscular or intranasal routes elicit robust, broadly cross-reactive antibodies that recognize diverse isolates, including ceftriaxone-resistant strains, even though the tested formulations did not confer protection in mice. By establishing mRNA-LNPs as a viable platform for gonococcal antigen testing, this work lays the foundation for optimizing constructs, adjuvants, and routes for developing mRNA-based vaccines against gonorrhea and other antimicrobial-resistant bacteria.

microbiology↗

bioRxiv2026

Eukaryotic Initiation Factor 5B (eIF5B)-Driven Translational Control Impacts Oral Squamous Cell Carcinoma Pathophysiology

The non-canonical translation of specific mRNAs has been implicated in oncogenesis and cancer progression. We previously identified eukaryotic Initiation Factor 5B (eIF5B) as a key factor in Internal Ribosome Entry Site (IRES)-mediated translation of a subset of mRNAs encoding anti-apoptotic proteins. Here, we demonstrate that EIF5B is predominantly expressed in cancer cells compared to other cell types in the Oral Squamous Cell Carcinoma (OSCC) microenvironment. Higher EIF5B mRNA and protein expression are associated with poor patient outcomes. We show that eIF5B depletion in OSCC cells blunted pro-growth, pro-inflammatory, and pro-angiogenic signaling pathways and significantly increased TNF-related apoptosis-inducing ligand (TRAIL)-induced cell death. This is achieved through decreased translation of mRNAs encoding critical factors associated with OSCC pathophysiology. Importantly, the level of interaction of eIF5B with tRNAiMet was significantly higher in OSCC cells compared to non-cancerous fibroblasts. This suggests that OSCC cells (but not non-cancerous fibroblasts) rely heavily on eIF5B for translation initiation. In an in vivo flank xenograft model using nude mice, eIF5B knockdown in UMSCC-29 cells led to a significant reduction in tumor volume compared to control tumors. Also, the immunohistochemical analysis of the xenografted tumor sections demonstrated decreased staining intensity of critical factors associated with OSCC pathophysiology in eIF5B-depleted tumors relative to controls. Collectively, our data demonstrate that OSCC cells are uniquely dependent on eIF5B-tRNA interactions to sustain translation of pro-survival mRNAs. Targeting eIF5B disrupts these oncogenic programs, sensitizing OSCC cells to apoptosis and suppressing pro-angiogenic and pro-growth signaling.

cancer biology↗

bioRxiv2025

Bridging Gaps in Antibody Responses and Animal Welfare: Assessing Blood Collection Methods and Vaginal Immunity in Mice Immunized with Intranasal Gonococcal Vaccines

Assessing antibody titers and functional responses is essential for evaluating vaccine efficacy, yet the impact of blood collection methods on these immunological assessments remains unclear. Retro-orbital (RO) blood collection is commonly used but significant complications can occur. Increasingly, investigators have adopted alternative blood collection approaches, such as saphenous vein (SV) sampling to improve laboratory animal welfare. This study compared RO and SV sampling in the development of a Neisseria gonorrhoeae (Ng) vaccine, evaluating Adhesin Complex Protein (ACP) and multiple transferable resistance (Mtr) E protein (MtrE) as antigen candidates. Epitope mapping revealed that ACP and MtrE possess multiple, highly accessible B-cell and T-cell epitope clusters, reinforcing their immunological potential. Following intranasal immunization with rACP, rACP+CpG, and rMtrE+CpG, we assessed the specificity, magnitude, kinetics, and functional quality of immune responses elicited by the immunization regimens. Out of 45 comparisons, only eight significant differences were detected in antibody titers, while the human serum bactericidal assays revealed no differences between RO and SV in antigen-immunized groups. However, antibodies elicited by rACP alone or ACP+CpG in SV samples restored 30.05% and 75.2% of human lysozyme hydrolytic activity compared to 19.3 and 59.9 % in RO, respectively suggesting that SV sampling may be more reliable for assessing functional antibody responses. Beyond its immunological advantages, SV sampling reduces stress, minimizes ocular trauma, and improves animal welfare, making it a viable alternative to RO collection. Given its widespread use in vaccine research, standardizing SV sampling could improve data reliability, ethical compliance, and translational relevance in preclinical studies.

microbiology↗

bioRxiv2023

Mass spectrometric analysis and biostimulatory effects of boar seminal gel, saliva and semen in pigs

The present study aimed to identify novel biostimulatory compounds in boar seminal gel (SG), saliva and semen using Gas chromatography-mass spectrometry (GC-MS). SG alone and its combined application with saliva (SG+saliva) and semen (SG+semen) also studied to train young boars. SG alone and SG+Saliva investigated for estrus induction in gilts and sows. Distilled water (DW) exposure was kept as control. SG, saliva and semen screened for total 105, 96 and 89 compounds. The highest concentration was of alkanes followed by sugar alcohols, then hydrocarbons, amino acids and fatty acids. Elaidic acid is the novel compound identified in pigs. Other compounds were tridecenol, undecane, hexadecone, eicosane, tetracosane etc. Further, young males (64.86%) were able to get trained. Significant higher (p<0.05) number of males got trained in exposure to SG (80%), SG+saliva (75%) and SG+semen (75%) than control. The time (hrs) taken by young boars to get trained on exposure to combination of SG+saliva (244{+/-}22.19) and SG+semen (216{+/-}13.14) was lesser (p<0.05) than SG (356{+/-}61.85) alone. Interval (hrs) for exhibition of different sexual behaviour by males on exposure to SG, saliva and semen was lesser (p<0.05) than control. Estrus was induced in 61.25% of females. Significant (p<0.05) higher number of females showed estrus response to exposure of SG (72.72%) and SG+saliva (69.23%) than control. Interval taken to exhibit estrus was lesser (p<0.05) in females exposed to SG+saliva (201.88{+/-}12.66) than SG (262.14{+/-}20.06) alone. Interval (hrs) for exhibition of different sexual behaviour by females on exposure to SG+saliva was lesser (p<0.05) than control. In conclusion, novel compounds with biostimulatory properties have been identified in boar SG, saliva and semen. The combined exposure of SG with saliva and semen have more intense biostimulation effect than SG alone. Such compounds and biostimulatory effects can be exploited for augmenting reproductive efficiency in pigs.

animal behavior and cognition↗

bioRxiv2022

Spatial transcriptomics reveals distinct and conserved tumor core and edge architectures that predict survival and targeted therapy response

We performed the first integrative single-cell and spatial transcriptomic analysis on HPV-negative oral squamous cell carcinoma (OSCC) to comprehensively characterize tumor core (TC) and leading edge (LE) transcriptional architectures. We show that the TC and LE are characterized by unique transcriptional profiles, cellular compositions, and ligand-receptor interactions. We demonstrate that LE regions are conserved across multiple cancers while TC states are more tissue specific. Additionally, we found our LE gene signature is associated with worse clinical outcomes while the TC gene signature is associated with improved prognosis across multiple cancer types. Finally, using an in silico modeling approach, we describe spatially-regulated patterns of cell development in OSCC that are predictably associated with drug response. Our work provides pan-cancer insights into TC and LE biologies, a platform for data exploration (http://www.pboselab.ca/spatial_OSCC/) and is foundational for developing novel targeted therapies.

cancer biology↗